A fermentation technique used in France in which a carbonic maceration (carbonic acid mash) is started with part of the grapes (usually about half). A normal alcoholic fermentation is then started by adding conventionally destemmed, mashed grapes. The resulting fermentation carbonic acid then displaces the oxygen to the top. In this process, the whole grapes - without destemming - are placed in several tranches in a fermentation container. In the grape must that escapes through the weight, spontaneous fermentation then begins in the intact berries and the escaping carbon dioxide produces the effect that is usual at carbonic maceration.